8. Eukaryotic Cell Structures & Functions

Endosymbiotic theory is supported by the discovery of non-nuclear DNA in the ______ and ________ organelles.

According to the endosymbiotic theory, which of the following is likely the ancestor of the mitochondria?

The following organisms have important roles as symbionts with plants and fungi; describe the symbiotic relationship of each organism with its host: cyanobacteria, mycorrhizae, Rhizobium, Frankia.

NAME IT These nitrogen-fixing prokaryotes provide nitrogen fertilizer in rice paddies; they live symbiotically in the cells of the freshwater plant Azolla.

Which of the following characteristics regarding eukaryotic organelles supports the endosymbiotic theory? Select all that apply. (NCLEX/HESI/TEAS)

a. Eukaryotic ribosomes are 70S just like prokaryotic ribosomes.

b. Mitochondria and chloroplasts have 70S ribosomes like prokaryotes.

c. Mitochondria and chloroplasts are double-membrane organelles similar in size to bacteria.

d. Mitochondria and chloroplasts have their own circular chromosome.

e. Eukaryotes can have cell walls like prokaryotes.

Describe the endosymbiotic theory. What evidence supports the theory? Which features of eukaryotic cells are not explained by the theory?